Composite structures often are fabricated in a laminated array, sometimes including a core, such as of foam, sandwiched between a pair of outer structural skins and bonded thereto by some sort of adhesive. The skins often are reinforced with fibrous material, and the composite structures typically are generally pla ar in geometry due to limits in processing technology. Thermoset resin systems predominantly are used with such composite structures.
Due to labor intensity in processing composite structures of the character described, such as those fabricated from thermosetting resins, the structures usually are relatively expensive. They also are not readily repairable. Fully cured structures offer few free polymer chains for molecular level bonding to a repair material.
On the other hand, thermoplastics are reformable, readily repairable and inherently much more impact-resistant than thermosets. The use of thermoplastics for continuous fiber reinforced structures has, however, been limited by an inability to achieve consolidated structures with suitable dispersion of resin and fiber reinforcements. There is a need for a new and improved method of fabricating advanced composite structures using thermoplastic materials or matrices.
An example of an advanced composite structure with which the invention is readily applicable is shown in copending application Ser. No. 191,250 , filed May 6, 1988, assigned to the assignee of this invention, and which is incorporated herein by reference now abandoned. That application involves an irregularly shaped housing, such as for a dynamoelectric machine, and includes various components such as conduits, electrical devices, etc. embedded within the core of the composite structure.
This invention is directed to satisfying the above needs and solving the problems described.